Improvement in roasting and desulphurizing ores and minerals



'11 )Nrn TATES ATENT rica.

SIMON STEVENS, OF NE? YORK, N. Y.

Specification forming part of Letters Patent No. 413.046, dated June 7,1504.

T 0 all whom it may concern Be it known that I, SIMON STnvENs, of thecity and State of New York, have invented a new and useful Process ofRoasting and Desulphurizing Ores and Minerals; and I do hereby declarethat the following is a full and exact description of the same.

The nature of my invention consists, first, in using hydrocarbon vaporsor gases as fuel for roasting and desulphurizing ores; secondly, ineffecting the roasting and desulphurizing of ores by burning the vaporsof hydrocarbons mixed or combined with either ordinary or superheatedsteam; and, thirdly, in the collecting from pyritous ores the gold andsilver which they contain, by roasting or burning such ores in the flamefrom hydrocarbon vapors or gases, quenching the hot ore in water, thenwashing out andfloating away the light earthy matters, and collectingthe gold and silver by means of amalgamation with mercury, or onamalgamated plates, these several operations forming a continuedprocess.

The ordinary mode of roasting ores is in heaps, mounds, ovens, orfurnaces, using solid fuel, such as wood, coal, coke, or peat. For fuelI use volatile hydrocarbons, such as petroleum, coal-oil, earth-oil, orequivalent substances which may be easily converted into vapor by heat.By the combustion of such vapor mingled with air, or with air and steam,I of: feet the roasting and desulphurizing of ores and minerals, and inthe case of the ores of the precious metals the roasting, washing, andamalgamating may be united, so as to form one continuous process. 7

I will now proceed to indicate the operations and apparatus necessaryfor carrying my 'invention into effect; but as these may be greatlyvaried,and do not form part of this invention, a brief description isdeemed sufficient.

- For converting the liquid hydrocarbon into vapor or gas any of theknown devices for that purpose may be used. It is not necessary, or evenpreferable,to subj ect the liquid to destructive distillation so as toproduce a permanent gas. The petroleum or liquid hydrocarbon is placedin a tank or reservoir, and by means of a tube conducted to a boiler orvessel to which heat may be applied,so as to convert the liquid intovapor or gas. This vapor may be mixed with air as it is produced; or theair may be caused to mingle with it at the instant of combustion. Steam,common or superheated, may

also be mixed with it in like manner, so asto regulate the combustionand assist in roasting and desul phurizin g the ores. The combustion ofvapors thus prepared is effected by devices alreadyknown, and thereforeneed not be particularly described.

The jets or burners used for delivering the vapor, air, and steam shouldbe arranged in a row or series,so as to furnish the amount of heat orthe hot products of combustion in contact with the ore to be roasted.This maybe done in many ways. The simplest is 'to place the pulverizedore on the hearth of an oven, or in a reverberatory furnace, so that theflame and heated gases may play upon it; or theore may be broken intosmall pieces and placed in a revolving cylinder, such as is sometimesused for distilling coal, and the flame thrown through the cylinder asit revolves. The axis of the cylinder maybe inclined, so as to cause theore to pass through it as it is revolved. Other means may be used tomove or stir the ore as it passes through the cylinder.

Another and in many respects a preferable mode of effecting the roastingof the ore is to bring it in fine powder into the flame. This may beaccomplished by having the ore fed from a hopper, so as to fall into theflame from the row of gas or vapor burners, or by driving the ore intothe flame with an air-blast; or the combustion may be carried on in anupright shaft or chimney, the gas or vapor jets being arranged in rowson one, two, or more sides of the shaft, either at the topor bottom ofit; or when it is necessary to bring a large volume of flame in contactwith the ore several parallel rows of jets may be arranged at differentheights on the inside of the shaft. The ore in fine powder is to be fedinto the top of the shaft or chimney, and as it falls it will becompletely roasted by the flame or hot gases and vapors. Steam orsuperheated steam may be injected through the jets which convey thehydrocarbon vapors. Air also,for supporting combustion,may be mingledwith oilvapor; or it may be introduced through separate pipes.

When ores of the precious metals,as pyrites containing gold,are roastedby my process, the entireoperation of roasting, washing, andamalgamating the gold may be carried on in a continuous manner. As theoreis roasted,it should fall into water,where, by stirring andagitating, it is washed,and the light and earthy matters carried off bya current of water. The heavier parts containing gold and silver willsettle to the bottom, and may be combinedwith mercury or collected onamalgamated plates in any of the usual modes well known to miners andmetallurgists. As the hot ore falls directly into the watcr,the latterwill be kept at a high temperature, and therefore the amalgamati on ofthe precious metals will be readily effected.

Having thus described my invention and the several modes in which it maybe applied,what I claim, and desire to secure by Letters Patent of theUnited States, is

1. The use of hydrocarbon vapors or gases as fuel in the roasting anddesulphurizing of ores or minerals.

2. The desulphurizing and roasting of ores by means ,of a combined blastor current of hy- SIMON STEVENS.

WVitnesses:

MUNROE OI-IUBB, G120. 1. WILLEY.

